A plurality of test procedures, which require rapid analysis at the site of occurrence, at the individual or at the object to be measured in order to shorten reaction times or to facilitate decision-making that justify further, at times expensive special analyses, are known in both environmental analytical chemistry, forensic chemistry and clinical diagnostic procedures. Such tests are increasingly also carried out by lay persons in order to save costs or to directly satisfy the need for information. This circumstance substantiates the challenge to simplify complex analytical operations to the extent that a generally understandable handling is achieved at a low operator level.
Rapid tests, which are based on test strips, which perform one-step analyses of individual substances autonomously with a sample fed manually and a visual or device-based evaluation, correspond to the state of the art.
This procedure is difficult in the case of more complex biochemical analytical procedures when multi-step sample preparations precede an analysis and the sample thus processed must subsequently be fed to the analytical unit. If additional substances must be analyzed in a single sample with a defined offset in time and possibly under regulated thermal conditions, an on-site test can usually be carried out mostly with a great effort only. Additional operations, such as reaction or connection steps, require either trained operating personnel or stationary automatic laboratory analyzers, which are equipped with corresponding robotics, compartmentalization and air conditioning. Analytical processes thus become either too cumbersome and too error-prone or too expensive to continue to be still able to claim being a rapid on-site test. The most important factors, which increase the complexity of the process for the user to a considerable extent, are reproducible sample preparation, fluid management and thermal management of a sample. It is important in terms of avoiding errors, specially when a process shall also be able to be used as a mobile process, for example, by the police during use in the field, to design the process such that it comprises the smallest possible number of handling steps and the simplest possible handling steps for the user, combined with automatic processes. Experience has shown that a minimum of manual procedures leads to a maximum of precision in the result.
An example of the automation of fluid management and sample processing is shown by EP 0 965 042 B1. It describes an immunochemical process, which is characterized by a high degree of segmentation of the sample processing process and the reaction pathway. The individual process steps are made possible by the connection of independent components with one another via mobile parts. A large number of individual parts are needed to transfer a sample, which is located in a test cassette. The sample is connected to the analytical element via mobile components. However, it is a one-analyte system, which does not take into account the different ways of processing of different analytes contained in a sample in one process.